Note: Javascript is disabled or is not supported by your browser. For this reason, some items on this page will be unavailable. For more information about this message, please visit this page: About CDC.gov.

The former Chemical Commodities Inc. facility in Olathe, Kansas, engaged in the resale ofchemicals that were surplus, off-specification, recycled, or had exceeded their specified shelflife. The facility, in operation from 1951 until 1989, stored chemicals on site in both aboveground and underground storage tanks as well as drums, boxes, barrels and other miscellaneouscontainers (1). Significant surface soils, subsurface soil and groundwater contamination hasbeen identified on site, primarily due to spills and leaks of chlorinated solvents over the years.The Environmental Protection Agency (EPA) placed the site on the National Priorities List(NPL) in May 1994. The EPA Project Manager for the Chemical Commodities, Inc. (CCI) siterequested that the Agency for Toxic Substances and Disease Registry (ATSDR) review recentindoor air sampling results for several homes next to the CCI site and determine if these levelsare of public health concern (2).

Several chemicals were found in the indoor air of each of the five homes located adjacent to thissite including chemicals which may be related to groundwater contamination at the CCI site.However, many of the chemicals detected in the indoor air are not believed to be related to theCCI site. Regardless of the source of these chemicals, no adverse health effects are expected atthe levels found in the indoor air. Outdoor air samples contained three chemicals whose sourceis unknown (methylene chloride, pentane and acetone). The source(s) of detected chemicals inthe outdoor air samples is(are) unknown. We recommend the source(s) of these chemicals beidentified and evaluated.

The levels of chemicals reported in indoor air are not a public health concern. However, werecommend that these homes be checked for seasonal variations for those chemicals that may belinked to soil gas movement. Additionally, as the extent of groundwater contamination in thearea is better defined, we recommend evaluating other homes to determine if indoor air sampling is warranted.

BACKGROUND

The Chemical Commodities Inc. site, which occupies about 1½ acres, is in a largely residentialarea of Olathe, Kansas (Figure 1). The shallow groundwater contamination includes a plume ofdissolved chlorinated solvents such as tetrachloroethylene (PCE), trichloroethylene (TCE),chloroform, carbon tetrachloride 1,1,1 trichloromethane (TCA) and 1,1,2,2, perchloroethane(PCA) (1). A dense non-aqueous phase liquid (DNAPL) has been found below the shallowgroundwater in the areas of highest contamination. A recovery trench was constructed in 1991to remove this DNAPL, primarily TCE, from the shallow aquifer. Additionally, a groundwaterextraction and treatment system was installed to address the dissolved phase groundwater plume(1 ).

Residences border the property to the north and across Keeler Street to the west. The shallowgroundwater plumes, approximately 15-20 ft below the surface extends to the north and west ofthe site below homes adjacent to CCI. Past soil vapor and crawl space sampling indicate apotential for volatile compounds in the soil and groundwater to transport through soil vapor intoindoor air (1,3,4).

The potential for health hazards due to chemical releases at the CCI at the Olathe site wasreviewed by the Centers for Environmental Health at the Centers for Disease Control (CDC) in1983 at the request of the EPA (5). This CDC evaluation concurred with existing EPArecommendations to address on- site chemical hazards, which included removal of contaminatedsurface soils. The CDC recommended these actions be taken as soon as possible to preventfurther releases. When considering the impact of this site on public health, CDC evaluationnotes the elevated levels of chemicals in the surface soil on site; but that the data were notsufficient to evaluate the impact on the surrounding homes. Therefore, CDC agreed that site"investigation is needed to quantify the extent of contamination both on and off the site" in orderto assess any potential impact on the surrounding community due to contaminated soils orairborne contamination (5).

ATSDR evaluated results from ambient air, and residential air monitoring conducted in 1989 bythe EPA. Levels of site contaminants, most notably PCE and TCE, were elevated downwind ofCCI facility (6). Additionally, these compounds were found in the three residences sampled. PCE and cis-1,2-DCE were found in two of the residences. However, the levels found both inambient and residential air, were not considered either an imminent or long term health hazard(7). At that time, ATSDR recommended reducing ambient air emissions from the site, and tocontinue periodic monitoring of indoor air. Specifically, ATSDR recommended samplingacross different seasons as weather conditions can effect contaminant migration and build-up inbuildings (7).

In 1996, the EPA requested that ATSDR review environmental data collected at CCI in Olathe,Kansas, specifically soil vapor and flux measurements from the ground into the air. A review ofdata available at that time indicated measurable chlorinated solvents in soil gas and flux of someof these chemicals into the ambient air including TCE, PCE, PCA, TCA and cis-1,2-dichloroethene (DCE) (1). Additionally, groundwater isopleth maps indicated that contaminantshave migrated off-site and the plumes were currently underlying residences adjacent to the CCIsite to the north and west (1). Although these data indicated the potential for movement of thesevolatile compounds into ambient air and indoor air, the flux data alone were not consideredsufficient to assess human health threats at the site (4). ATSDR recommended additionalsampling in basements, crawl spaces and other confined spaces in the vicinity of the plumes (4). Concurrent ambient air monitoring was also recommended. ATSDR also noted that soil gas mayalso migrate through underground utility lines which "may result in VOC intrusion into homesnot located directly over the contaminated plume."(4) ATSDR's site review and update inDecember of 1996 reiterated these recommendations. (8)

ATSDR completed a public health assessment, as mandated by CERCLA, on the CCI site inApril of 2000 (9). This report summarizes site conditions and past ATSDR work on CCI. Inaddition, the author reviewed air sampling conducted in 1997 in the crawl space below fourhomes adjacent to the CCI site (10), concluding the levels of VOCs found at that time "did notpose a health concern for crawl space air."(9) ATSDR's earlier recommendations to sampleambient air at the site and indoor air in homes above the groundwater contamination werereiterated. Additionally, the author concurred with EPA's current actions to prevent public access to the site and to continue treating contaminated groundwater in the area.

DISCUSSION

Indoor air samples were collected by the EPA in five homes near the CCI site in October andNovember of 2000 (11) (Figure 1). These samples were collected in response to earlier datawhich indicated some plume related chemicals were found in the soil gas, and in crawl spacebelow homes in the area. The five homes were chosen due to their proximity to the groundwatercontamination associated with the CCI site (11). Although there is some overlap, all of thehomes previously sampled for volatile chemicals in crawl space air are not included here. Thehomes (labeled A,B,C,D and E in Figure 1) are adjacent to CCI, lying north and east of thefacility.

Soil gas pathway

It is possible for chemicals which evaporate easily into the air, which are called volatilechemicals, to travel through the air spaces in soil above groundwater and enter buildings. Crawlspaces below buildings, basements and storage areas not often opened, are particularlysusceptible to collecting these volatile chemicals. Many variables can influence if theconditions are right for chemicals to enter the home and to accumulate. If the chemicals are present in the the living spaces within a home, residents will be exposed to these chemicals in theair.

The major volatile contaminants in the CCI plume are TCE, PCE, TCA cis-1,2-dichloroethene,carbon tetrachloride and 1,1,2,2-perchloroethane (PCA) (1). Chloroform, methylene chloride,benzene, toluene, xylene and other chlorinated solvents are found in the groundwater at lowerlevels (1). Of the major plume contaminants, PCE, TCE and DCE were found in soil-gassamples in the vicinity of the sampled homes in 1996 (1). The presence of these chemicals in thesoil gas above the plume indicates a potential for them to migrate into buildings over the plume.

Historical air sampling of the crawl spaces below the homes indicate these chemicals and othersare found in crawl space below the homes (3,10). Crawl spaces are not occupied as often as theliving spaces within the home and these chemicals were not present at levels that would be ahazard for the occasional entry into the crawl space(7,9). Sampling studies conducted by theEPA in 1989 in three homes, one of which is included in the present study, found PCE, TCE,TCA, cis-1,2-DCE hexane, toluene and methylene chloride in crawl space air (3). Additionalsampling of the crawl space below four homes in 1997, two of which were included in thepresent study, found low levels of TCE, TCA, DCE, benzene, ethylbenzene, toluene, xylene,chloroform and 1,3-dichlorobenzene in some of the homes (10). The presence of thesechemicals in the crawl space below the home does indicate they may also be present in the livingspace within the home. Therefore, air samples from the living areas of these homes were takento determine if volatiles from the plume may be in the indoor air.

The 24 hour samples are an average air concentration for that period of time. It is likely theactual concentration of the chemicals in the indoor air fluctuated throughout the day. The threeday average is the average of all three of the 24 hour samples taken within the same residence. Where no chemical was found in the air sample, the limit of detection was used for the 24 hoursample when calculating a three day average. Although it is possible that the chemical was notpresent at all, the limit of the detection is the greatest amount that could have been there and notseen by the laboratory. Therefore assuming the chemical was present at this level is a 'worstcase' scenario, providing for a conservative assessment of any potential health effects.

Outdoor air

The majority of chemicals found in the outdoor air samples do not seem to be related to the CCIgroundwater plume. TCE, TCA, chloroform, DCE and DCA found in the groundwater plumeare not reported in any of the outdoor air samples (Table 2). Only PCE, of the major plumecontaminants was found. PCE was detected in two of the four air samples at 14 and 51 µg/m3(micrograms of chemical per cubic meter of air). Benzene, toluene, xylene and ethylbenzene, arealso site related. However, groundwater levels are low such that they are not expected to impactambient air. Benzene, toluene, xylene and ethylbenzene have many other potential sources asthey are present in gasoline. Isopropyl alcohol, pentane and acetone were found in all fouroutdoor air samples, but are unrelated to site contamination. Chloromethane was found in threeof four samples near the detection limit.

Methylene chloride is a site related chemical and was detected in all four outdoor samples atlevels higher than other chemicals (440-810 µg/m3). However, methylene chloride is a minorplume constituent in the area sampled. Methylene chloride, acetone and pentane levels werenoticeably higher in outdoor air than the other compounds detected. Levels reported formethylene chloride are above what may be expected for ambient air. Potential source areas forthese chemicals near these homes have not been identified.

Historically, site related contaminants were found in ambient air. The EPA conducted outdoorair monitoring in 1989 (6). The earlier sampling was limited to those chemicals expected as sitecontaminants. TCA, TCE and PCE, all major site contaminants, were found at higher levelsdownwind than they were up- wind at the CCI site (6). This indicated the CCI site was a sourceof airborne contamination in 1989 (6). The EPA removal of contaminated surface soils would beexpected to reduce volatile emissions from the CCI site. However, since the wind direction onthe sampling days is not known, one cannot determine the impact of the CCI site on ambient airquality. These samples do provide an indication of the ambient air quality outside of thesampled homes during indoor air sampling. However, it should be noted the detection limitswere higher for the analysis of the four outdoor samples than for the analysis of the indoor airsamples (Appendix B). For several of the chemicals found at low levels in the homes, nodetermination can be made as to if these chemicals were present at the same low levels inoutdoor air. This is discussed further below when addressing the indoor air samples.

Indoor air

The indoor air samples indicate several potentially site- related as well as non-site relatedchemicals were present in the homes on the days sampled (Table 3). This is not alarming asthere are many sources of chemicals in the home, both natural and manufactured. These datacannot distinguish the source of the chemical measured, but a discussion of potential sources isprovided for perspective. Regardless of the source of the chemicals found in these homes, thefollowing health evaluation will look at residential exposure to all of these chemicals.

Of the five residences, residence A is closest to the site, and directly over part of the plume. Residence E is the farthest from the site and may or may not lay directly over the groundwatercontamination. TCE was found in all five homes with three day averages ranging from 2.7 to5.9 µg/m3 (Table 3). PCE was found in two homes with averages of 4.7 and 8.9 µg/m3. TCA wasfound in three homes with averages of 2.8, 27 and 31 µg/m3. Chloroform was found in threehomes with three day averages from 2.6 to 4.2 µg/m3. Methylene chloride was found in all fivehomes with averages ranging from 2.0 - 11.1 µg/m3. DCE was not detected in any of the homes.

Volatile chemicals reaching the homes through the soil-gas pathway would be expected to bepresent in the groundwater, soil gas and then would accumulate in the homes similarly, forsimilar chemicals. For example, TCE, PCE and TCA have similar chemical properties whichdefine how they move through the environment. All are found in the groundwater near thesehomes and all were found in the soil gas sampled near the homes in 1996. However, TCE andPCE were only detected together in two homes (B and E). TCA was found in two homes wellabove the method detection limit (C and D) and one home at the detection limit (home E), buttwo of these homes did not show PCE. Therefore, even though these three chemicals occurtogether in the groundwater plume and in the soil gas; they do not occur together in the homes.

PCE, TCE , TCA and DCE have all been detected in past sampling events in the soil gas in thevicinity of the homes as well as in some of the crawl space air samples taken in 1989 and 1997.Chloroform was not analyzed for in the 1996 soil gas samples, and was found in one of the fourcrawl space samples from 1997 at the method detection limit. Although analyzed for in the1989 sampling, the method detection limit of 42 µg/m3 for chloroform is much higher than levelscurrently being found in the homes; therefore, if chloroform was present at current levels, itwould not have been seen in the earlier samples.

Methylene chloride is also a component of the groundwater plume near home A. However,methylene chloride has not been previously analyzed for in either soil gas or crawl space air. The levels reported in indoor air are ten to 100 fold lower than those seen in outdoor air duringthe same days of sampling, ranging from 2 µg/m3 to 11.1 µg/m3 in indoor air and ranging from440 µg/m3 to 810 µg/m3 in outdoor air. This difference is especially marked since all sampleswere taken for 24 consecutive hours.

Although only PCE of the major plume components was found in the outdoor air samples, itshould be noted that the detection limits for the outdoor air samples were higher than the indoorsamples. The detection limits for TCE, PCE and chloroform were higher than most of thedetected levels reported for indoor air (Appendix B). Therefore, the data allow us to draw noconclusions about the indoor levels of these chemicals and the quality of outdoor air on the dayof sampling. TCA, which was found at 27 and 31.7 µg/m3 in two of the homes, was not seen inthe outdoor air. These indoor TCA levels are greater than the detection limit for outdoor air(4.5-5.9 µg/m3 ) indicating levels of TCA were greater in these homes than the ambient air on those days.

The fuel components, benzene, toluene and xylenes were found in all five homes, with tolueneand xylene occurring at the highest concentrations (Table 3). Ethylbenzene was found in two ofthe five homes. These chemicals are found in the groundwater in the vicinity of the homes, butat very low levels in the part per billion range. It is unlikely their presence in the home is duesolely to the plume. Soil gas sampling in 1996 did not detect measurable quantities of thesechemicals in the air below the ground. These chemicals are found in gasoline, solvents and otherproducts which may be present in the home. Also, it should be noted that all four of the outdoorair samples contained benzene and toluene (Table 2).

Other chemicals seen in the indoor air of some of these homes includes alcohols, ketones,aldehydes, styrene, carbon disulfide and some solvents (Table 3). Many of these chemicals areused industrially, but their presence in the indoor air samples does not indicate a directconnection to an industrial site. Chemicals may be present in the home due to consumerproducts such as cleansers, toiletries, paints or chemicals used for hobbies. Chemicals may beused as solvents for oils, waxes, resins, varnishes, dyes, lacquers and rubber and in otherindustrial processes (Table 1). If left within the product, the chemical may release into the airwhen the product is brought within the home. So building materials, textiles, plastics and rubbermaterials used in the home may contribute low levels of organic chemicals to indoor air. Someof the chemicals found in indoor air may be due in part to natural sources. For example, variousalcohols, ketones and aldehydes may be produced by plants and microorganisms. The types andlevels of the chemicals found in these five homes are not unusual.

Public health evaluation

The presence of these chemicals in indoor air does not necessarily present a health hazard. Theamount of chemical an individual is exposed to, as well as the duration of exposure, must betaken into account in order to understand if any health effects would be expected. These twofactors together define the exposure conditions and the dose of the chemical. The dose is theamount of chemical that an individual takes into their body. When considering a residentialexposure to indoor air, the route of exposure is by breathing and the intake into the body throughthe lungs.

The duration of exposure to indoor air in homes can vary greatly. In this case, the durationwould be the amount of time per day, or per week an individual spent in the home. Althoughmany individuals work, go to school or leave the home for periods of time over the week, thismay not always be the case. Therefore, in an effort to protect all individuals, a full timeexposure, 24 hours a day, is assumed in this evaluation. Additionally, when evaluatingtheoretical cancer risk, this full time exposure is taken as a lifetime exposure, a full 70 years ofresidency. Although it is extremely unlikely that any individual in these homes will meet theseconditions, the most conservative exposure scenario is chosen here to be protective of allconditions. It should be noted that going to school or to work every day for 8 hours could reducethis assumed exposure by as much as 1/3.

There is a potential for indoor air levels to vary seasonally and over time as site conditionschange. Days of heavy heating may actually pull soil gas into the homes and the closed uphomes for insulation may allow it to remain in the home. Significant changes in the CCI plumeover time may increase or decrease any contribution of solvents to the homes which may becoming from the plume. Additionally, changes in home usage, hobbies and new consumerproducts will influence indoor levels of these chemicals regardless of the impact from the CCI groundwater contamination.

Non-cancer health effects

ATSDR establishes minimum risk levels (MRLs) for exposures to chemicals based on theavailable medical, toxicological and epidemiologic data. Often these data include studies onpeople exposed to chemicals in the workplace, and laboratory animal studies. There areuncertainties in applying both the worker studies and animal studies to the general population. Therefore, these MRLs are often 100 to 1000 times lower than the level which may have resultedin a health effect. As such, the MRLs are conservative values below which no adverse healtheffects are expected.

MRLs are established for a route of exposure (e.g. breathing) and a duration (acute, intermediateor chronic). Chronic MRLs are established for a lifetime exposure. Eleven of the chemicalsdetected in homes near CCI have chronic MRLs. Most of the chemicals with established MRLsare chlorinated solvents and fuel components. In all cases, the amount of the chemical seen inthe indoor air is well below the established MRL, indicating that no non-cancer adverse healtheffects are expected (Table 3). TCE, ethylbenzene and benzene do not have chronic MRLs, butthe intermediate MRLs are given in Table 3. The balance of the chemicals do not have MRLsestablished.

A chronic MRL was not set for ethylbenzene (13). However, the intermediate MRL is believedto be protective for chronic effects. A chronic-duration study in rats defined a NOAEL of250,000 ppb (1,090,000 µg/m3) (14). This NOAEL is greater than the NOAEL fordevelopmental effects on which the intermediate MRL is based (97,000 ppb, 420,000 µg/m3)(15). The sensitive end point of developmental effects results in a more conservative, and in amore protective MRL, than would have been derived from the chronic-duration study. Therefore, chronic exposures below the intermediate MRL are not expected to result in adversehealth effects.

As with ethylbenzene, no chronic MRL exists for benzene (16). Chronic-duration studies forbenzene exposure do exist, and a human LOAEL can be defined at 3,000 ppb (9,570 µg/m3) (16).However, pancytopenia, or a decrease in red cells, white cells, and platelets in the blood , is seenat this exposure level and is considered a serious effect which cannot be used to establish anMRL. There is not a LOAEL at levels below that found in this study that is less serious. ThisLOAEL for noncancer health effects in humans is 2000-fold greater than benzene levels seen in these homes. These levels do not pose a healthy hazard for non-cancer health effects.

Both the acute and intermediate MRLs for TCE are based on neurological effects: headachefatigue and drowsiness in humans breathing up to 200,000 ppb (1,080,000 µg/m3) during aworkday (acute exposure), and decreased wakefulness and sleeping heart rates in rats exposed to50,000 ppb (270,000 µg/m3) for 6 weeks of forty hours a week of exposure (intermediateexposure) (Reviewed by ATSDR, 17). The only chronic duration study in animals for inhalationof TCE showed no respiratory, cardiovascular, hematological hepatic, endocrine, dermatological,occular or body weight effects at exposures as high as 600,000 ppb (3,240,000 µg/m3) for 104weeks of exposure, 40 hours per week. Kidney effects were seen, in the male rats only, at300,000 ppb (1,620,000 µg/m3) but not at the lower dose of 100,000ppb ( 540,000 µg/m3)(Reviewed by ATSDR, 17). However, these effects are believed to be species and sexdependent, and are not expected to occur in humans (17). Therefore, available data indicate nonon-cancer health effects would be expected due to chronic exposures to the levels of TCE foundin the indoor air at CCI (2.7-5.9 µg/m3).

MRLs do not exist for many of the alcohols, ketones and aldehydes. However, these compoundsare generally readily metabolized by our bodies and in some case produced in our bodies duringnormal metabolism. The small amounts found in indoor air do not pose a health hazard.

Cancer

As with non-cancer health effects, the levels of chemicals found in these homes are far belowlevels that are known or believed to cause cancers, either in human or animal studies. However,some of the chemicals are classified as known or suspected carcinogens. Table 4 shows theclassification based on reviews by the EPA, the National Toxicology Program (NTP) and theInternational Agency for Research on Cancer (IARC). Of the chemicals evaluated, benzene isclassified as a known human carcinogen (18,19,20). PCE and TCE are classified as probablycarcinogenic to humans by the IRAC and are considered to be reasonably anticipated to behuman carcinogens by the NTP, but not currently classified by EPA. Chloroform, methylenechloride and styrene are all believed to have some degree of carcinogenic potential (Table 4). The balance of the chemicals either have not been reviewed or there is not enough data toclassify them in terms of their potential to cause cancer.

BenzeneBenzene is the only compound found in these air samples which can be linked definitively in human studies with cancer. However, the levels seen in both indoor and outdoor air are not believed to be a hazard. Studies examining workers show benzene exposure has been associated with leukemia, but no detectable excess of leukemia is seen in workers who are below 40,000 ppb-years (125,000 µg/m3-years), or an exposure of 1000 ppb (3190 µg/m3) for a duration of 40 years (21). There is uncertainty in the extrapolation of cancer incidence data from occupational studies, usually involving exposures higher than those seen in the environment, to low-level residential exposures. However, based on the levels of benzene in these homes, and the EPA unit risk (18) for cancer incidence, there is no apparent increased risk of cancer due to these exposures, even for long term residential exposure.

Trichloroethylene and TetrachloroethyleneThe chlorinated solvents TCE and PCE are classified as potential human carcinogens (20). However, although the carcinogenicity of these compounds has been shown in animal models, the weight of evidence for carcinogenicity in humans is not definite (Reviewed by ATSDR, 17). Additionally, studies which explore why these chemicals are toxic to animals indicate the same mechanisms may not be relevant to humans, especially at the low doses seen in indoor air at this site (Reviewed by ATSDR, 17). Considered individually, there is some doubt about either chemical's carcinogenicity. Currently, IRIS does not provide a cancer slope factor to provide theoretical estimates of cancer risk for exposures to these chemicals.

One study of cardboard manufacturing workers shows a link between TCE exposure in theworkplace and kidney cancer (22). However, other epidemiological studies for workers exposedto only TCE vapors show no higher incidence of cancer than controls (reviewed by ATSDR, 17). There are several studies which include TCE exposure as well as other workplace chemicalswhich show increased cancer rates. An association has been reported between low levelexposure to TCE in drinking water supplies and leukemia and other cancers, but these studies arealso confounded by the presence of other chemicals (reviewed by ATSDR, 17). Similarly,epidemiological studies examining PCE exposure are inconclusive. Epidemiologic studies ofdry cleaning workers, exposed to PCE and other solvents, have shown evidence of increasedmortality due to cancer including: kidney, bladder and cervical cancer (23), reviewed byATSDR 24). Other studies of dry cleaning and laundry workers suggest a link with cancers ofthe lung, cervix, esophagus, kidney, skin. Therefore, workplace exposures to multiplechemicals, including PCE, TCE and other solvents,in the air, have been linked to increasedcancer mortality. Although indoor air samples at the CCI site show exposures to thesechemicals, along with other solvents, similar health effects are not expected. The levels of thesechemicals at the CCI site are 100 to 1000 times lower than occupational exposures believed tohave some link with cancer mortality.

ChloroformThere are no studies which evaluate the potential for cancer after being exposed to chloroform in the air, either for humans or in laboratory animals. The basis for considering chloroform a possible human carcinogen includes 1) animal studies where animals ingested the chloroform and 2) general population studies on human consumption of chlorinated drinking water. Both sets of data are problematic. Results of the animal studies vary dramatically from indications of carcinogenicity, to one study which indicated chloroform was protective against a specific cancer in male rats (reviewed by ATSDR 25). The authors summarize that the method of dosing the animals was influencing the outcomes of the animals studies (25). Although studies of communities on chlorinated water may suggest an association with cancer, these associations are weak and remain unproven. Additionally, although chloroform is known to be in chlorinated drinking water, many other compounds are also found as a result of chlorination. Any association between chlorinated drinking water and cancer, if it exists, may or may not be due to chloroform. However, the EPA has established a unit risk (or slope factor) for human exposure based on extrapolation from the animal studies (18). Based on the indoor air levels of chloroform and this unit risk, there is no apparent increased risk of cancer due to these exposures, even for a long term residential exposure.

Methylene ChlorideOne study of the workers exposed to methylene chloride indicated a significant increase in bile-duct cancers (26). The workers were exposed to as much as 1,700,000 ppb for up to 28 years. However, other studies have shown no link between deaths due to cancer and lower levels of methylene chloride in the workplace (<475,000 ppb) (reviewed by ATSDR, 27). Methylene chloride has been shown to cause tumors in animal studies at 500,000 ppb and 2,000,000 ppb (reviewed by ATSDR, 27). These studies, taken together with evidence which indicates the same mechanism of toxic action may exist within animals and humans, support the designation of methylene chloride as a probable/possible human carcinogen. However, the levels of methylene chloride seen here in indoor air are well below any cancer studies. Based on the indoor air levels of methylene chloride and the EPA established unit risk (18), there is no apparent increased risk of cancer due to these exposures, even for a long term residential exposure.

StyreneThe IARC has categorized styrene as possibly carcinogenic to humans. Neither EPA nor the NTP has classified styrene at this time (18,19). The IARC cites several epidemiological studies which indicate an association between exposure to styrene in the workplace and lymphatic and hematopoitic cancers (20). There is limited evidence for cancer in animal studies but not lymphatic and hematopoitic cancers. However, a reactive metabolite of styrene can be measured in both humans and animals exposed to high levels of styrene. This metabolite be responsible for changes in cells consistent with the development of cancer (20). Therefore styrene is a possible carcinogen. Although there is no available unit risk factor for styrene, the air levels seen in these homes are well below worker exposures which may be linked to cancer.

Summary of Cancer Health EffectsFor all chemicals addressed here, the measured levels in these five homes are far below the levels which have been seen to produce cancers in animal and human studies. Therefore, the ability for these exposures to result in increased cancer is highly unlikely (as represented in the unit risk factors) and essentially unmeasurable even if it occurred at the calculated incidence. In practical terms, there is no expectation of increased incidence of cancer due to chronic exposures to these chemicals, taken either singly or together, at the measured levels.

Children and other sensitive populations

ATSDR recognizes that infants and children may be more vulnerable to exposures than adults incommunities faced with contamination of their air, water, soil, or food. As part of its ChildHealth Initiative, ATSDR is committed to evaluating children's special interests. Consideringexposure to indoor residential air at the CCI site, children may have an increased vulnerabilitydue to the following factors: 1) children weigh less than adults, resulting in higher doses ofchemical exposure relative to body weight, 2) the developing bodily systems of children cansustain permanent damage if toxic exposures occur during critical growth stages and 3) childrenhave a breathing zone lower to the ground. Similarly, the elderly may be susceptible due tochanges in the body's ability to detoxify chemicals and repair damage which come with aging. As a conservative screening tool, the MRL is designed to account for these factors. Whenconsidering how well the experimental data can be applied to the general population, anuncertainty factor for human variability is used in developing the MRL. This uncertainty factoraddresses the application of the MRL to sensitive populations, including children and the elderly,which may not have been involved in the study population on which the MRL is based. Therefore the MRLs are considered protective of these sensitive populations. Although, thereare still many unknowns about the carcinogenic process and the bodies ability to defend againstit, the cancer estimates, where done, and the weight of evidence discussions above are believed to be protective of the general population by their conservative nature.

SUMMARY

Several volatile organic chemicals were found in the indoor air of each of the five homessampled adjacent to the CCI facility. The presence of some of these chemicals may be consistentwith soil gas accumulation from the groundwater plume beneath the homes. However these datacannot establish this. Many of the chemicals found are not site related, but may be due to othersources within the home. Regardless of the source of these chemicals, there is no apparenthealth hazard indicated by these data. No discernable adverse health effects are expected basedon exposure to these chemicals over a lifetime.

The above analysis is based on the assumption that the three 24-hour samples are representativeof the residential exposures. Any changing site conditions that may cause soil vapor and indoorair levels to fluctuate such as further migration of the contaminants, seasonal effects, andchanges in building use, may impact indoor air quality. This evaluation is limited to the currentmeasured conditions.

The air samples collected in October and November 2000 only address the five homes locatednorth of the CCI facility. Groundwater contamination also extends west of the facilityunderlying homes in that direction (1). The EPA is currently in the process of determining thearea impacted by the groundwater plume. ATSDR concurs with these actions to betterunderstand the extent of groundwater contamination due to the CCI facility. Differences inhome construction, geology, building use, utilities and the basements can impact soil gasaccumulation on a building by building basis. All buildings above the CCI plume should beidentified and evaluated to determine if indoor air sampling is warranted. Similarly, the homesimmediately to the east of the facility should be evaluated to determine if there is any potentialfor the plume to impact these homes as well.

The outdoor air samples are not sufficient at this time to make a health call. Although thechemicals detected were below levels of health concern, the representativeness of these datacannot be determined. Without knowledge of the source(s) of acetone, methylene chloride andpentane, there is no way to determine if these samples represent typical outdoor air levels due tothe source(s). Additionally, the levels of these chemicals in the outdoor air may indicate a lightindustrial source in the vicinity of the homes. If so, other chemicals not analyzed for in thisstudy may be released by the same site. The source (s) of these chemicals should be determined and their impact on this residential area evaluated.

CONCLUSIONS

1. The levels of chemicals detected in the indoor air of homes sampled near the CCI facility, arenot expected to result in any observable adverse health effects, either cancer or non-cancer.

2. The shallow groundwater plume from CCI may underlie other homes in the community. Theair samples reviewed here do not address indoor air in these other homes

3. The source(s) of the methylene chloride, pentane and acetone detected in the outdoor airsamples are unknown. These samples cannot be used to evaluate the public health implications of those sources.

RECOMMENDATIONS

1. Resample these homes to check for seasonal variations in those chemicals which may be linked to soil gas movement.

2. Continue to identify the extent of groundwater contamination, especially in the adjacentresidential areas. Identify and evaluate other homes and buildings above and adjacent to the CCIplume for the potential to accumulate soil gas within their structures. Conduct representativesampling within the living space for constituents of the groundwater plume to determine if thesechemicals are present in the buildings.

3. Identify potential sources for the methylene chloride, acetone and pentane seen in the outdoorair samples. Evaluate the potential impact on the residential areas surrounding the facility.

Fuel components (benzene, toluene, ethylbenzene, xylene and decane) are all found ingasoline and solvents used in the home. Benzene is also produced while smoking.

Chlorinated solvents (PCE, TCE, TCA, chloromethane, and chloroform) are used inindustry primarily for degreasing and cleaning operations or in chemicalmanufacturing processes. TCE may be part of a solvent blend in a consumerproduct such as adhesives, paints/strippers, spot removers, varnishes andpesticides. PCE is used in textile processing and dry cleaning operations. TCA isfound in adhesives, cleansers, paint removers, wood stain and varnishes. Chlororform, in addition to the uses of the other solvents, is produced as abyproduct of drinking water chlorination.

Alcohols (2-propanol, 1-propanol and 1-butanol) are produced naturally by plants andduring microbial degradation or fermenting processes. Alcohols are also used assolvents for oils, waxes, resins varnishes and rubber and in other industrialprocesses. 2-propanol is the same as isopropyl alcohol, or rubbing alcohol whichmay be used in the home.

Ketones (acetone, 2-butanone, 4,methyl-2-pentanone and 2-hexanone) may be used inthe production of adhesives, rubber cements, resins, dyes, lacquers, varnishes andeven as a food and fragrance additive. Acetone is actually the major componentof nail polish remover.

Aldehydes (propanal, butanal, pentanal and heptanal) may be used as disinfectants,preservatives, food flavorings, and in the manufacture of polyvinyl, plastics,rubber and resins. The aldehydes are also released from plants andmicroorganisms and will be byproducts of wood and fuel combustion. Aldehydeshave been found in foods both raw and prepared.

Other solvents and chemical intermediates (carbon disulfide, trimethylbenzenes, andstyrene) may be present in a myriad of products from food additives to pesticidesand are used in the chemical manufacture of paints, dyes, plastics, resins rubberfound throughout the home.

Table 2:

Summary of volatile chemicals found in outdoor air near five homes adjacent to the CCI Site, Olathe, KS. All values are shown µg/m3. Samples were collected in metal cylinders and analyzed for the volatile organic chemicals shown in Appendix A. Any chemical not reported here was undetected by the laboratory.

Sample NumberLocationDate of Sample

#16Home A10/30/00(ug/m3)

#17Home B11/17/00(ug/m3)

#18Home C11/20/00(ug/m3)

#19Home D11/06/00(ug/m3)

Average of samples

(ug/m3)

MRL a

(ug/m3)

Uncertainty Factor b

tetrachlorethene

51.0

(7.3)c

(7.1)

14.0

9.5

270

100

methylene chloride

670.0

810.0

580.0

440.0

610

1000

30

Benzene

3.9

4.3

3.6

4.0

4.0

12 (I)

90

ethylbenzene

5.0

(4.7)

(4.5)

4.3

4.5

4300

100

toluene

6.2

(4.0)

9.8

120.0

44.6

1500

30

m and/or p xylene

16.0

15.0

(4.5)

16.0

11.8

430

100

o-xylene

5.1

4.8

(4.5)

5.3

4.9

430

100

2-propanol

30.0

13.0

44.0

83.0

46.7

pentane

140.0

150.0

170.0

590.0

303

Acetone

220.0

230.0

200.0

150.0

193

31000

100

chloromethane

2.8

(2.2)

2.7

2.6

2.5

100

1000

a. Minimal Risk Level. An estimate of daily human exposure--by a specified route and length of time--to a doseof a chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not beused as a predictor of adverse health effects. The values shown here are expressed as µg/m3 and have beenconverted from the MRLs established in ppm. All values shown are the Chronic MRL unless designated as theIntermediate MRL (I).

b. Uncertainty Factor: Factor used to account for uncertainties in establishing an MRL. Uncertainty factors may beused to apply data on animals to human exposure, to account for human variability if a level of no adverse effect hasnot been defined. This factor is the fold margin between observed adverse health effects, or the lowest no observedhealth effects level, and the set MRL.

c. Values shown in parentheses are the chemical detection level for that air sample. On this table, the limit ofdetection is given for those compounds which were not found. It is possible the chemical was present at a level below the laboratory detection limit.

Table 3.

Summary of volatile chemicals found in residential air in five homes adjacent to the CCI Site, Olathe, KS. All values are shown µg/m3.

Home A

Home B

Home C

Home D

Home E

MRLa (µg/m3)

Uncertainty Factor b

Chlorinated solvents and others

trichloroethene

4.9

5.9

2.7

3.0

3.7

540( I)

300

tetrachlorethene

(3.4) c

8.9

(3.4)

(3.7)

4.7

270

100

1,1,1-tricholoethane

(2.8)

(2.8)

31.7

27.0

2.8

3800 (I)

100

chlororform

(2.5)

3.0

4.2

(2.7)

2.6

98

100

methylene chloride

2.0

2.4

4.6

11.1

2.2

1000

30

carbon disulfide

(6.3)

(6.3)

(6.3)

7.8

(6.3)

930

30

styrene

(2.2)

(2.2)

(2.2)

(2.4)

3.9

260

100

Chloromethane

3.4

4.7

1.3

2.6

4.4

100

1000

1,2,4-trimethylbenzene

(2.5)

(2.5)

9.4

2.9

17.1

1,3,5-trimethylbenzene

(2.5)

(2.5)

3.5

(2.7)

5.2

Fuel Components

Benzene

2.6

4.5

2.1

3.0

5.5

12 (I)

90

ethylbenzene

(2.2)

(2.2)

(2.2)

2.5

6.0

4300

100

toluene

21.0

11.8

45.7

31.3

32.7

1500

30

m and/or p xylene

4.9

5.4

3.2

3.9

42.7

430

100

o-xylene

(2.2)

2.2

5.6

2.4

19.3

430

100

decane

(12.0)

(12.0)

(12.0)

(13.0)

15.0

Alcohols

1-propanol

(5.0)

(5.0)

(5.0)

(5.4)

7.0

2-propanol

5.9

27.2

8.9

286.7

210.3

1-butanol

12.0

(6.2)

10.5

10.0

14.7

Ketones

Acetone

97.0

32.3

50.0

350.0

54.3

31000

100

2-butanone (MEK)

13.0

8.7

9.8

8.7

14.3

4-methyl-2-petanone

(8.3)

(8.3)

9.7

8.9

55.1

2-hexanone

(8.3)

(8.3)

(8.3)

(8.9)

13.0

Aldehydes

propanal

15.0

5.9

10.1

11.4

6.3

Butanal

18.0

10.4

12.1

(6.5)

12.3

heptanal

(9.5)

(9.5)

(9.5)

(10.3)

12.3

pentana

(7.2)

(7.2)

(7.2)

(7.8)

7.8

a. Minimal Risk Level. An estimate of daily human exposure--by a specified route and length of time--to a dose of a chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects. The values shown here are expressed as ug/m3 and have been converted from the MRLs established in ppm. All values shown are the Chronic MRL unless designated as the Intermediate MRL (I).

b. Uncertainty Factor: Factor used to account for uncertainties in establishing an MRL. Uncertainty factors may be used to apply data on animals to human exposure, to account for human variability if a level of no adverse effect has not been defined. This factor is the fold margin between observed adverse health effects, or the lowest no observed health effects level, and the set MRL.

c. Values shown in parentheses are the chemical detection level for that air sample. On this table, the limit of detection is given for those compounds which were not found. It is possible the chemical was present at a level below the laboratory detection limit.

Table 4.

Cancer classification for chemicals found in indoor air in five residences near the CCI Site, Olathe, KS.

Chemical

IRIS Classification a

IARC Classification b

National Toxicology Program c

Benzene

A -Known human carcinogen

Group 1 - Human carcinogen

Known to be a human carcinogen

Trichloroethylene

Withdrawn d

Group 2A - Probably carcinogenic to humans

Reasonably anticipated to be a human carcinogen

Tetrachloroethylene

None

Group 2A - Probably carcinogenic to humans

Reasonably anticipated to be a human carcinogen

Chloroform

B2 - Probable human carcinogen

Group 2B - Possibly carcinogenic to humans

Reasonably anticipated to be a human carcinogen

Methylene Chloride

B2 - Probable human carcinogen

Group 2B - Possibly carcinogenic to humans

Reasonably anticipated to be a human carcinogen

Styrene

None

Group 2B - Possibly carcinogenic to humans

Not listed

a. Environmental Protection Agency, Integrated Risk Information System (18).b. International Agency for Research on Cancer (20).c. National Toxicology Program, the U.S. Federal Department of Health and Human Services (19).

GLOSSARY OF TERMS

Adverse Health Effect:

A change in body function or the structure of the cells that can lead to disease orhealth problems.

Background Level:

An average or expected amount of a chemical in a specific environment. Or, amounts of chemicals that occur naturally in a specific environment.

Dose:

The amount of a substance to which a person may be exposed, usually on a daily basis. Dose is often explained as "amount of substance(s) per body weight per day."

LOAEL:

Lowest-Observed-Adverse-Effect Level. The lowest dose of a chemical in a study, or group of studies, that has caused harmful health effects in people or animals.

MRL:

Minimal Risk Level. An estimate of daily human exposure--by a specified route and length of time--to a dose of a chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects.

NOAEL:

No-Observed-Adverse-Effect Level. The highest dose of a chemical in a study, or group of studies, that did not cause harmful effects in people or animals.

No Apparent Public Health Hazard:

The category is used in ATSDR's Public Health Assessment documents for sites where exposure to site-related chemicals may have occurred in the past or is still occurring, but the exposures are not at levels expected to cause adverse health effects.

No Public Health Hazard:

The category is used in ATSDR's Public Health Assessment documents for sites where there is evidence of an absence of exposure to site-related chemicals.

Plume:

A line or column of air or water containing chemicals moving from the source to areas farther away. A plume can be a column or clouds of smoke from a chimney or contaminatedunderground water sources or contaminated surface water (such as lakes, ponds, and streams).

Public Health Hazard:

The category is used in ATSDR's Public Health Assessment documents for sites that have certain physical features or evidence of chronic, site-related chemical exposure that could result in adverse health effects.

Uncertainty Factor:

When scientists don't have enough information to decide if an exposure will causeharm to people, they use "uncertainty factors" and formulas in place of the information that is not known. The factors and formulas can help determine the amount of a chemical that is not likely to cause harm to people.

Agency for Toxic Substances and Disease Registry. Site review and update for ChemicalCommodities, Inc. Olathe, Johnson County, Kansas. Atlanta: US Department of Healthand Human Services; 1996, December 24.

Agency for Toxic Substances and Disease Registry. Memorandum to Danielle DeVoneyfrom Ben Puesta transmitting air sampling results from five homes near the ChemicalCommodities, Inc. Site in Olathe Kansas. Kansas, City Kansas. April 4, 2001.

Ninth report on Carcinogens: National Toxicology Program, US Department of Healthand Human Services; Research triangle Park, North Carolina. Available from URL:http://ehis.niehs.nih.gov/roc/toc9.html , last revised January 2001.